The regulation of cyclic AMP and cyclic GMP formation and metabolism will be examined. Studies will be conducted to characterize materials that influence cyclic AMP effects on protein kinase and phosphorylase kinase activation. Concentrations of cyclic AMP and cyclic GMP in plasma and urine from patients with a variety of metabolic and endocrine disorders will be examined to develop a new diagnostic tests and/or examine the pathophysiology of some disorders.